Various mechanisms which change the display screen of the flat panel display apparatus such as liquid crystal display apparatus to be tilted into a landscape (horizontal) orientation or portrait (vertical) orientation have heretofore been proposed. A screen orientation changing mechanism of a simple structure which conducts a combination of an operation for turning a display unit with an operation for moving the display unit in a vertical direction without using separate turning mechanism and vertical moving mechanism is disclosed in, for example, JP-A-Hei 11-338363.
In this mechanism, a bar like connecting member which is referred to as “link bar” is disposed between the display unit and a stand. The link bar is mounted at its upper end (rotary axis A) on the stand so that it is rotatable and its rotation angle can be kept. The link bar is mounted at its lower end (rotary axis B) on the display unit in a position offset from the center of the screen of the display unit, so that it is rotatable and its rotation angle can be kept. The display screen can be changed from a landscape (horizontal) orientation to a portrait (vertical) orientation by initially turning the display unit by an angle around the rotary axis B and then turning the display unit around the rotary axis A by an angle â.
However, the changing operation between the landscape and portrait orientation is not completed at one step in the screen orientation changing mechanism of the above-mentioned prior art flat panel display apparatus since it is conducted at two steps of rotary movements by the rotary axes A and B. Specifically if the changing mechanism is applied to large screen display apparatus, an extended period of time and labor is expended. Since the rotation center is not in the vicinity of the center of the screen, the rotary movement of the display unit at this time is larger than that around the central portion of the display unit, so that ease of rotation may be lost. As a result, a process for changing the orientation of the display screen may become very unstable.
The present invention was made in view of the above-mentioned problem. It is therefore, an object of the present invention to provide a flat panel display apparatus which is capable of conducting a transition between the landscape and portrait orientation of the display unit at one step and capable of turning the display unit around the substantial center of the display unit.